New azo dye.



Patented July 11, 1900.

'UNITED STATES PATENT OFFICE.

ALFRED THAUSS, OF ELBERFELD, GERMANY,

BRIKEN ()F ELBERFELI) 00., OF NEW YORK, N. Y., A

NEW YORK.

ASSIGNOR TO FARBENFA- CORPORATIQN or NEW AZO DYE- SPECIFICATION forming part of Letters Patent No. 794,568, dated July 11, 1906.

Application file-*1 film-ch 28, 1905. Serial Nu. 252,514.

To (tilwhom, it may concern:

Be it known that I, ALFRED THALss, doctor of philosophy, chemist, (assignor to the FARBENFABRIK as or ELBERFELD C0,, of New York) residing at Elberfeld, (:rermany, have invented a new and useful Improvement in New Azo Dyes; and I hereby declare the following to be a clear and exact description of my invention.

I have found that new and valuable azo dyestuffs can be obtained by first combining diazo compounds with the thiazol-sulfonic acid having the following formula:

- oil which I name meta-amidobenzenylthio-2-5- annoonaphthol-T-sulfonic acid, and then isolatmg from the reaction mass the resulting dyestuffs.

- ders soluble in water with a red color and being, dissolved by concentrated sulfuric acid with from a red to violet color. mordanted cotton from yellowish-red to bluish-red shades. 'hen on libel, these dyestulfs can be further diazotized and coupled with beta-naphthol, yellower and more deepened shades fast to washing being tuus obtained.

l n carryine out my new process practically I can proceed as follows, the parts being by weight: 15.1 parts of meta-nitrobenzaldehyde are added to a solution of twenty-six parts of 2-5-amidonaphthol-7-sulfonate of sodium in two hundred parts of hot water.

'lhe aldehyde enters quickly into solution with the production of the benzylidene compound. After the addition of a concentrated solution of thirty parts of sulfur and seventy five parts of crystallized sodium sulfid in water it is heated to boiling for twenty-four hours at a reflux condenser. \Vith disengagement of hydrogen snlfid the thiazol nucleus is formed, the nitro group being reduced at the same time. The solution thus obtained is then filtered in order to remove therefrom the precipitated sulfur and acidulated by the addition of sulfuric acid in order to precipitate the new compound. The acidthus separated in the shape of faint-yellow crystals is soluble with diiiiculty in water. It is converted into its sodium salt, which is easily soluble in hot water by means of sodium carbonate, and then freed from admixed sulfur by redissolving it from hot water. 37 .2 parts of this product are then dissolve in water with the addition of 15.6 parts of sodium carbonate and to the resulting solution the diazo derivative produced in the usual manner from 10.7 parts of orthotoluidin is added. The dyestutf thus formed is precipitated by the addition of common salt, filtered off, and dried.

The new dyestuff is after being dried and pulverized a reddish-brown powder, being soluble in water and in concentrated sulfuric acid (of 66" Ri'saumur) with a red color. it dyes unmordanted cotton red shades. When on fiber, the coloring-matter can be further diazotized and developed by means of betanaphthol, red shades of a yellower tint being thus produced, which are fast to washing.

The process for obtaining the above-named dyestuffs proceeds in an analogous manner on using other diazo compounds, such as the diazo derivatives of anilin, xylidin, orthoanisidin, or the like.

Having now described my invention and in what manner the same is to be performed, what I claim is 1. The herein-described new azo dyestutfs with the meta-amidobenzenylthio-2-5-amidoing, substantially as hcreinbefore described.

2. The herein-described new azo dyestufl obtainable by comb? ling diazotized orthotoluidin with the meta-ainidobenzenylthi0-2- 5-an1idonapht-hol-7-sulfonic acid having the .2 I v a 794,588

above-given formula, which dyestufi' is in the shape of its sodium salt a reddish-brown powder soluble in water andin concentrated sub furic acid with a red color; dyeing unmovdanted cotton red shades which can be further diazotized and developed-on the fiber by means of beta-naphthol, red shades of a yellower tint being thus obtained which are fast to washing, substantially as hereinhefore described.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

ALFRED THAUSS.

\Vitncsses: Y I

O'rro Rome, 7 J. A. Rn'rERsHAUs'. 

